Induction from underground power circuits into parallel communication services

The paper describes a powerful method for computing voltages induced into pilot/communication cables in the event of a sudden fault in a neighbouring underground power circuit. The model uses multiconductor travelling-wave theory and is able to compute transient as well as steady-state induction. Given results clarify the extent to which transient effects add to postfault steady-state induction. The various factors affecting the level of induction are investigated, leading to the proposal of a simple formula. This formula is accredited against the standard of the full model and appears to offer sound practical estimates.